Instructions For SAITO FG-17(AAC) 4-Stroke Gasoline Single

Fire wallAir inhalationpipeFuel feeding pipeRubber cap forgasoline-resistantFuel tank(200-250cc in capacity)aboveFuel levelAir inhalationpipeFuel levelto Carb nippleto Outside ofthe fuselageFig.4Gasoline-proof tubeFig.3Engine centerFilter with weightWithin 200mm (close as possible)Center of fuel tank5. Ignition system (Fig.5)The ignition system is designed to match our 4-stroke engines with automatic advancing system.However this ignition system is designed to be an anti-noise product, please isolate it completely from the receiver, servo, and battery to avoid a radio-interference trouble.Moreover, it is desirable to utilize a noise filter (line filter). Especially, each switch (for Ignition and for Receiver) should be isolated and set far from each ones.The function of each cord;(1) Plug cord (meshed high tension cord)The tip of the plug cap is designed exclusively for SAITO SP-1 Plug. When you put on the plug cap, insert it to the plug until the clip fits the groove on the plug (Fig.6;then you will hear clicky sound) to avoid coming off during flight. And then pull the plug cap to make sure that it won’t come off.When you put off, pinch the clip and pull up the plug cap (Fig.7).(2) Sensor cord (black /red/white cord)Connect with the cord from the sensor attached to the engine.(3) Battery cord (black/red cord)Please use the fully charged battery that has adequate spec. (6-8V, more than 1000mA is recommended.). Between the battery and main body, make sure to set anignition switch whose capacity is higher than 3A.Noise check (required)Caution: A gasoline engine generates a noise which has an adverse effect on RC adjustment unlike a glow engine. Please be sure to carry out a noise check each timewhile the engine is running before the flight. Since a noise which occurs during flight may lead to a large-scale accident, please carry out a noise check without fail.As a simple method, after starting engine you can check by removing the antenna of the transmitter and operate it about 50m away from the airplane. If there is nomalfunction, it is normal. Moreover, it is preferable to obtain advices from an expert of gasoline units.Plug capPlug cordMain unitSwitch (not included)Capacity: more than 3AFig.6Battery cordSensorFig.5Sensor cordBatteryVoltage: 6-8VCapacity: 1,000mA or higherFig.7*Sensor position and Power / Starting easiness;The ignition sensor can be moved to CW (advance the spark timing) or CCW (delay the timing) as Fig.8 shows.At the factory default the sensor is fixed on the center (neutral) position. The reason is related to the methods of enginestarting.・With an electric starter You can start wherever the sensor is fixed.So you can set the sensor as the rpm reaches maximum speed.・By hand flip (Manual start) Starting easiness depends on the sensor position.The factory default is set as you can start by hand flip and also get highest rpm in that range as possible.If you prefer easiness of hand starting, move the sensor to CCW direction to delay the spark timing. But then themaximum rpm will slightly decline.If you prefer power (highest rpm), move the sensor to CW direction. But then you can't start by hand flip but only withstarter.In addition by the feature of the ignition system, it heats up with engine running. When you restart the engine by handflip, you should open the throttle valve slightly while it's hot. And it's better to enlarge the choke without wetting the plug.For safety we recommend to use an electric starter.-3-View from frontProp rotation(CCW)CCWCWAdvanceSpark timingFig.8DelaySpark timingNeutral PositionHand starteasy area

6. Spark plugSAITO SP-1 spark plug is the standard equipment. Dimensions are as follows;Hexagon width: 8mmScrew size: UNEF 1/4-32Reach (with a washer): 5.5mmSpark-gap: 0.4-0.5mmFor replacement, please specify “SAITO SP-1”.Since our four cycle engine uses a mixed gasoline, please decide the numbers of flights by yourself and clean the spark plug. Pleasereplace, when it is degraded. (Consider the plug as consumable).7. CarburetorA carburetor with a pump developed exclusively for our small-size four cycle gasoline engine is mounted, instead of using mufflerpressure.Since the carburetor with a pump introduces the air from the air hole shown in the next figure, set it 2mm or more apart from the firewallor drill a hole on the firewall.When adjusting the carburetor, refer to Fig.9Main needle: To adjust the speed at the time of full open of the throttle valve.Slow needle: To adjust the speed from the idling to the middle speed.Turning each needle in clockwise direction, the fuel will become leaner and the rotation speed will increase. Turning it in counterclockwise direction, the fuel will become richer and the rotation speed will decrease.Fig.9Note: The carburetor for the gasoline engine is the assembly of very strict and delicate parts. So please make sure to use filtered gasoline.Moreover, DO NOT disassemble by yourself. If there’re any troubles regarding carb, please consult the shop from which you bought the engine.8. Engine mounting, muffler attachment, and breather waste disposalMake sure to use our standard engine mount attached. Otherwise, any other mount might cause troublesregarding heat or vibration.Make the firewall robust enough because this part has to endure vibration and torque caused by proprotation.It is preferable to apply some adhesives (such as screw lock) on the tip of M4 cap screw to avoid looseness when you install the engine.To ensure that cooling wind passes through the engine and muffler, the cowling should be devised. Alsomake the air flow outlet larger than the inlet. Building some baffles inside the cowling appropriately willenhance the cooling efficiency. Insufficient cooling may cause engine trouble such as overheat or mufflerlooseness.The muffler should be securely tightened with screw lock in the procedure to tighten up a double nutusing two spanners.(Adhesives, such as a screw lock agent, are effective against looseness and leakage.)For breather treatment, there is also a method in which the aluminum pipe, etc. are fixed at the muffleroutlet to diffuse the hot air together with exhaust gas into the air. (Breather may function by simplyejecting the tube from the engine)And one of the effective way of disposal is, to set a brief filter made by a small case and a tissue inside asthe figure shows.CowlingBaffleCool airMuffler outletExhaustFromBreather nippleAluminum pipeFrom9. Preparation before engine start (assuming break-in)To outsideBreatherfuselage(1) Please mount the engine on a robust and parallelized test bench or on the fuselage. (In either case,nipplethe engine should be fixed and immobile.)(2) Check whether the throttle valve can be fully closed and opened certainly.(3) Check whether each wiring of the ignition system is connected certainly.(4) Use 300-400cc tank for the test bench.(5) For piping, only connecting the carburetor with the tank is needed.(6) For fuel, prepare a mixed gasoline with volume ratio of “gasoline : oil” “20 : 1”Smallcase(7) Prepare a well balanced 15”x 6” carbon-made prop (Bolly or Mejzlik).Tissue*Prop attachment positionSince our 4-stroke gasoline engine can be manually started in forward direction (CCW from the front view) of the rotation,fix the prop in the position which facilitates vigorous clanking.(8) When starting with an electric starter, also attach a spinner. (This way of start is recommended for safety.)Note: Please tighten up the prop regularly at least once in ten flights. Especially for a wooden prop, it tends to compressed so thatthe nuts are rather easy to be loosen so please confirm carefully that the nuts are tightened adequately.(9) Unlike 2-stroke engines it is difficult to judge clearly the peak condition on 4-stroke engines. Prepare a tachometer to preventover-throttling or overheat.-4-

(11) In order to check discharge of the breather, attach a heat-proof and gasoline-proof transparent tube.(12) Prepare a battery for the electric starter.Caution: If there’s anyone stands forward, be sure to have them move behind the airplane prior to start the engine. Also keep in mind that the exhaust smoke isharmful for health. Keep away one of your arm holding the airplane away from the prop. On starting the engine, move to the rear of the airplane. Make needleadjustment or other control from the rear. If the airplane cannot be fixed, ask your assistant to hold the airplane for safety.10. Method of starting the engineThe following is the procedure using an electric starter for the engine mounted on the airplane.(1) Fill up the tank with fuel. (Be sure to turn off the switch of the ignition system during filling up the fuel.)(2) After confirm that the throttle stick is located at the full-close position, turn on the transmitter switch. Then turn on the receiver switch to check throttle valve and otheroperation. After that, fully close the throttle valve.(3) Open the main needle to 1 1/2 2 turns or so. (This value is not the peak value.)(4) Power on the ignition system.(5) Open the throttle valve about 1/4 from the full close position by using the throttle stick. (Starting with excessively opened throttle is dangerous since the airplane jumpsforward.)(6) Apply the starter to the prop and activate for about 5 seconds to start the engine.11. Break-inAs Break-in is an important procedure to pull out the maximum performance of the engine, it must be cautiously implemented.The purpose of break-in is initial lubrication and adjusting of mobile parts under the condition with rich fuel mixture.Never make the fuel mixture lean. Lean fuel mixture could cause seizure even if the engine drops to idling and runs at low speed.(1) After filling up the fuel tank, start the engine as described in the above section “10” and operate it at a low speed in the condition for about 5 seconds.(2) Next, in the condition of (1), fully open the throttle valve, turn back the main needle to make the air-fuel mixture very rich in the range where the engine does not stall(5,000 rpm or less). Operate in this condition with 2 (or more) tanks. (Conduct this step checking the density of the exhaust and the breather’ waste oil (inky-blackwaste oil)).(3) Next, after filling up the tank, re-start the engine. With the throttle valve fully opened, throttle the main needle and operate the engine for one tank at 7500 – 8,000 rpm.(4) Next, after filling up the tank, re-start the engine. With the throttle valve fully opened, turn the main needle from the rich to the peaks several times. When the peakbecome stable, open the throttle valve from low speed to high speed several times to check the response. And gradually elongate the time of high-speed operation.Conduct this operation for one tank.(5) When the revolution is stabilized at peak, the ground-level break-in is completed. After adjusting the tappet gap in the manner of section “14”, adjust the carburetoraccording to the following section. The running-in is completed by performing some 20 flights in a little rich condition. Subsequently, the flight should be performed insuch a rich condition as far as not to influence the flight.12. Adjustment of carburetorThe principal method of adjustment is the same as that for our glow engine* The slow needle is set so that idling rotation may be 1800rpm to 2100rpm at the factory default. However, since it may vary depending on the condition at the time ofoperation, adjust it so as to meet the operating condition. (For the slow needle’s reference value, refer to the figure in the section “7”).In principle, a carburetor is adjusted by first achieving peak (the highest revolution) with the main needle and then performing idling (low speed revolution) with the throttlevalve and the slow needle. (Unless the peak is certainly achieved, idling adjustment will be difficult and not stabilized.)(1) After filling up the fuel tank, start the engine in the manner of Section “10” and then fully open the throttle valve with the throttle stick.(2) By turning the main needle depending on the rotating meter and the exhaust sound, achieve peak carefully.* As for adjusting the main needle in the case of actual flight, setting the peak in the perpendicular attitude with a propeller in the upward direction is recommended ifit’s possible. In that adjusting, it’ll be rich enough in the horizontal attitude so it’s more similar to the condition during the actual flight.Caution: Over closing the main needle is very dangerous because it may cause knocking and propeller nut loosening. Then, turn the main needle CCW immediatelyto make it rich a little.(3) Next, close the throttle valve until the engine operates stably with an idling rotation of around 1,800 - 2,000rpm, adjusting the slow needle with the (-) screw driver andthe throttle valve carefully.*Since the richness level of the air-fuel mixture varies corresponding to the nature of the airframe, please adjust it depending on the user’s skill.Generally, in a scale flight in which the stability of a low-speed zone is considered as important and the engine is operated slowly, adjust the air-fuel mixture to berelatively lean. In an acrobatic flight in which the early standup from a low speed is considered as important, adjust the air-fuel mixture to be slightly rich.(4) After the idling is set, get the throttle valve slowly fully opened. If the revolution becomes slow or goes up suddenly, adjust carefully until it changes linearly from idlingto peak, by fine-tuning with the slow needle.(5) After the above adjustment is completed, open the throttle valve from idling to peak quickly. If the revolution does not achieve peak immediately but get delayed as thethrottle valve is fully opened, fine-tune the main needle and perform the same process from idling to peak quickly. Repeat this carefully until the response improves.* The key to make the engine last for long life is operating with the slightly rich condition as far as it doesn’t effect to the flight.Adjustment is needed depending on the engine attachment direction, the propeller, the fuel, the plug, the climate condition, etc.During flights, please fine-tune so that low speed, medium speed, and high speed match best with the airframe.-5-

13. Normal operation, maintenance, and additional information(1) Even for regular use, when you start the engine please run with rich condition for 30-60sec to warm up the engine. And when youstop, take a minute of idling to cool the engine. At the last flight of the day, make sure to stop by fuel-cutoff in order to make no fuelremain in the carb.(2) When you store the engine, make sure to remove all fuel from the tank.(3) Please charge the battery of the ignition system and RC device enough. (Since an ignition system generates high voltage, be carefulof electrification.)(4) For discharge of the waste oil (breather), connect a heat-proof and gasoline-proof tube to the breather nipple to eject the waste oil, ordiffuse it together with exhaust.(5) Lubrication for piston, connecting rod, bearing or cam gear is a blow-by lubrication in which the oil in the fuel goes into the crankcase from the clearance between the cylinder and the piston. Therefore the engine life is affected by the property of the fuel oil.Please use reliable oil.(6) Since over closing the main needle causes overheating, adjust a little more rich than peak.Over closing leads to knocking or engine failure and has an adverse effect on the connecting rod and the cam gear. The case wherethe airplane achieves peak completely at the time of ascent is a proper peak of the engine during flight.(7) After completing ground break-in or operating the engine for one hour, adjust tappet gaps (valve clearances) by following procedureto compensate initial wearing, while the engine is cold (Fig.10).(a) Remove the plug and rocker arm covers of the cylinder.Tappet adjustment(b) Turn the prop slowly forward by hand, to stop the rocker arm. Further turn theprop, to bring the piston to the TDC (Top Dead Center) of compression stroke.(c) Use the attached wrench and hexagonal wrench to adjust the gaps indefinitelyClose to "0" with no limitclose to zero within the range compression exists. If the gap is lower than 0,Limit gauge(0.1mm)the valve has to be opened at all phases so the compression doesn’t occur.After adjustment, please put on the spark plug and turn the prop forward toMust not be insertedcheck if the compression is enough.(over gap)(d) On checking the gap, securely tighten (but not excessively) the lock nut.Fig.10* In the case of the engines for vehicle, small gap is given to tappets to absorb valveelongation. In the case of SAITO engines, gap becomes larger during operations due to thermal expansion of the cylinder (made ofaluminum). Therefore set the gap indefinitely close to zero while the engine is cold.Note: Occasionally check tappet gap by those procedure. When the attached gauge (limit gauge, t 0.1mm) comes to be inserted, gap hasbeen enlarged beyond the allowable limit. Make an adjustment to lessen the gap. Tappet gap is one of the most important factors in themaintenance of 4-stroke engines. Operating the engine with the tappet gap enlarged excessively will cause poor performance or troubles.(8) When connecting the exhaust pipe to the cylinder or attaching the prop nut, apply thin coat of silicon rubber (not excessively) on thethread before tightening. This prevents leakage or loosening.(9) Occasionally tighten the prop nut and exhaust nut (while it is hot).(10) When stopping the engine after the day’s final flight, please be sure to stop it with fuel cut and see that the fuel does not remain inthe carburetor. Moreover after the flight is completed, extract the fuel from the tank without fail and store it.(11) See to it that the storage of the battery and the fuel cause no accident.(12) If the engine is not operate for a long period of time, remove plugs, rear cover, rocker arm covers and wash them with alcoholenough. Then, after lubricating them, assemble them in the original condition with a plastic bag on.(13) Please notice that our guarantee will not cover any breakage or trouble on the engine causedby your disassembling or modification. If disassembling becomes necessary, ask repair forthe shop from which you bought the engine.(14) Notes for purchasing parts: Please give orders to the shop from which you bought the enginewith engine name, part name or number, and marking (alphabet on the lower face of rearcover).(15) Take an extreme care for safety when operating the engine or flying the model airplane not tobother others.(16) Muffler maintenance; Because all of our gasoline engines use oil-fuel mixture, there tend to becarbon buildup inside the muffler as shown in the picture. It will cause some problems on theexhaust outlet and consequently reduce the power. Therefore cleaning/removing carbon everyabout 50 flights is recommended. Using a parts cleaner spray is effective way to remove the carbon inside. Actually, it depends onthe quality of the oil so when you feel the power loss, please check inside the muffler.(17) An engine for a model airplane is not a toy. Handle it with an extreme care.All specifications and models are subject to change without notice.SAITO SEISAKUSHO, CO., LTD.22-7, 3-chome, Tokagi, Ichikawa-shi, Chiba prefecture 272-0024, JapanPhone: 047-378-4156FAX: 047-378-4155-6-

SAITO FG-17 Parts ListNo. DescriptionQ'tyNo. Description01 Cylinder106 Piston107 Piston pin108 Piston pin retainer209 Piston ring148 Valve retainer (Cotter)210 Connecting rod149 Rocker arm cover269 Intake manifold (Intake pipe)174 Muffler114Cylinder screw set14-1,-21set15 Crankcase117 Rear cover (Back plate)119 Breather nipple120 Front ball bearing122 Rear ball bearing123 Crankshaft27283132Taper collet & Drive flange27-1,-2Prop washer & Nut28-1,-2Crankcase screw set31-1,-2,-3Engine gasket set32-1,-2,-3,-4,-5,-6,-811ea.111set38 Tappet139 Pushrod1Pushrod cover & Rubber seal40-1,-2,-341 Rocker arm42Rocker arm screw & Nut42-1,42-243 Rocker arm pin2ea.12ea.2Valve spring & Keeper & Retainer47-1,-2,48Muffler manifold set75-1,8082-1 Carburetor complete1set2ea.1set21setCarburetor body assembly83-1 15,-1-27,-1-28,32-5,91-185 Full throttle needle88B1set46-1,-280 Muffler nut1set35 Cam gear407587137 Steel washer set471ea.33 Cam gear housing36A Cam gear shaft46Valve set (In & Ex)Q'tyThrottle barrel assembly82-1-5,-1-9,88B,89Throttle lever88B,90-189 Idle needle909195Carburetor screw & spring tor gasket ngine mount set95-1,-2,-3,-4,-5,-611set111set1set1set110 Anti loosening nut1152 Screw-pin (For drive flange setting)1153Electronic ignition system153-1,-2,-3,-4,-51setPump assembly160 1-25,-1-26153-11set153153-2153-4153-3

SAITO FG-17 is a 4-stroke gasoline engine exclusively for model airplanes which is designed with emphasis on high performance, durability, and weight saving. Its parts are modified to adapt to the gasoline engine based on FA-100 glow engine, equipped with carburetor with a pump, ignition system and small-size spark plug matched to our engine.